5 What do you know?
It is implicit in the idea of crowd-sourcing prediction that the crowd members are making guesses that are not just random stabs in the dark but are informed by some knowledge about the situation. For example, if you were guessing how many sweets are in the jars in Figure 3, you would have at least a rough idea of what would be a likely number.
There is also evidence that some people are consistently able to make guesses that are much better than the average. Phillip Tetlock’s team at the US government-funded Intelligence Advanced Research Project (Iarpa) claims to have identified ‘super-forecasters’. Their unusual talents make them highly successful at predicting world events, and able to perform better than established experts. Almanis presumably hope that their system of identifying and rewarding accurate prediction will enable super-forecasters to emerge, whose abilities can then be put to use.
However, even if super-forecasters manage to be highly successful without being experts they probably still have a reasonable level of knowledge about the field where they are making predictions.
Studies have consistently shown that most people are surprisingly inaccurate at estimating facts about the society they live in.
You can explore this in the next activity.
Activity 8 How many senior citizens?
What proportion of the population of the UK are 65 or more years old?
Surveys show that most people believe the proportion is about 37%.
With your Fermi problem-solving skills, you can easily do much better!
Assume that the average length of life is 80 years. That can't be far out for people in the UK.
Assume that the proportion in all age groups is the same. That can't be far out either, but if anything is likely to overestimate, rather than underestimate, the proportion of older people.
The span from 65 to 80 is 15 years, so a Fermi-style estimate would be 15/80.
In the Python console, do the following calculation (multiplying by 100 is to convert to a percentage).
The result is 19%, a little over a half of what people tend to believe.
The actual figure in 2014 was 17.4%. Even though the proportion of the population who are 65 or over is steadily increasing, by 2024 it is still only forecast to be 19.9%.
The next section looks at what psychological research suggests are possible reasons why our estimates are often very inaccurate.